Excavation slated to begin in April at Bonito Lake

Removal of material from the lake may take 18 months to two years

A small excavator with the suction end of the blue water line dips into the lake. In back, is the end of the bypass line dumping water over the spillway of the dam.(Photo11: Courtesy Photo/David Tremblay)

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RUIDOSO – Excavation of sediment, ash and debris that washed into Bonito Lake after the Little Bear Fire in 2012 is set to begin in April, Alamogordo City Engineer Bob Johnson said.

Johnson and Rob Richardson, a civil engineer with Bohannan Huston Inc., responded Tuesday to a request from Lincoln County Commissioners for an update on the project to restore the lake that was used for recreation and as a major water source for Alamogordo before the fire and subsequent flooding.

Bonito Lake is owned by the city of Alamogordo in Otero County that's 66 miles southeast of Ruidoso in Lincoln County.

Alamogordo received 50 percent upfront funding for the value project from the Federal Emergency Management Agency on Sept. 20, 2014, and signed an agreement with Bohannan Huston as engineer of record to prepare the project design. A bid was awarded in August 2017 to Smithco Construction, and a notice to proceed was issued Nov. 6, 2017. Requirements included constructing a temporary coffer dam, about 38 percent complete, and a diversion pipeline, which is 90 percent complete, Johnson said.

Richardson said he grew up in Lincoln County and spent summers fishing at the lake and stream.

“It’s an honor and privilege to be part of this project and to help the city (Alamogordo) put Bonito back to full storage mode,” he said. “It’s an interesting and challenging project.”

An overview of the restoration work at Boito Lake shows the pipeline and dam construction, with a blue water pump used to move river water to the pipeline.(Photo11: Courtesy Photo/David Tremblay)

Before excavation could proceed, environmental and biological clearance was needed from the U.S. Army Corps of Engineers, and calendar allowances were required to work around the nesting season of the Mexican spotted owl, which can be disturbed by loud noises. However, the equipment used to drive the pylons for the coffer dam removed the noise concern, he said.

“They should be done with that by mid-March,” he said. Once the lake is “dewatered,” the contract with Smithco calls for removal of 250,000 cubic yards of material from the lake. The funding from FEMA is “in process,” for removal of the estimated 550,000 cubic yards that need to be removed to restore the lake to its 2,961 capacity, he said.

Officials hope to use the drained lake opportunity to replace valves on the dame and make other infrastructure improvements with the approval of the Dam Safety Bureau of the State Engineer’s Office, Richardson said. About 150,000 yards of burned material washed into the lake during flooding.

In response to questions from commissioners, Richardson said Alamogordo’s contract with Smithco requires the company to establish a baseline for the conditions of county roads that will be used to haul the material from the lake to a quarry. The company also must return the roads to their pre-project condition when things wrap up, he said.

Richardson is working with the state Department of Transportation on a traffic plan that will include signs warning of heavy truck traffic, lower speed limits and turning trucks caution signs. Between 10 to 20 trucks will be moving per hour, depending on the load capacity, he said.

Lincoln County Commissioner Dallas Draper said that type of truck traffic could be a problem for campers in the national forest when the summer tourist season is underway.

For the material to be placed in the quarry owned by Len Stokes in the Copper Mountain area, it has to pass a test to show it contains no more than a 15 percent moisture content, and has to be compacted at the quarry to create a stable 5 percent moisture limit, essentially dry, he said.

For the first time since the Little Bear Fire, photographer David Tremblay spotted the fire lookout tower from his vantage point at Bonito Lake and could see that everything burned all the way to the tower, setting the stage for massive runoff into the lake with the rain that followed.(Photo11: Courtesy Photo/David Tremblay)

Commissioner Tom Stewart asked if the levels of different metals and materials in the soil were typical and if Johnson considered anything “hazardous.”

“In my opinion, no, not hazardous,” Johnson replied.

“I find it ironic that Alamogordo is assuring us everything is OK,” Stewart said. “Local municipalities made the mistake a long time ago to allow Alamogordo (in Otero County) to purchase (the lake in Lincoln County) and move water from one basin to another, which would not be permitted today. To be clear about what’s occurring. You want the water, but you don’t want the waste. I thought you would take it south of the county line to Three Rivers. I have concerns about where (the material) is to be deposited.”

The permit mandates that the site be a minimum half mile from any caves and streams, Stewart said. But there is a stream that looks like an intermittent stream to him, and how can they be sure an elaborate system of caves don’t exist underground, he asked.

“People live on their wells” Stewart said. “You know how extensive caves are. The permit says no known, but the last time I looked Snowy River (Cave Formation ) was pretty extensive.”

Johnson said he had no additional information on caves, but based on permitting and review, nothing is found within the boundaries. Whether caves or a dry arroyo that could run in a major storm event could affect groundwater caution that is not the case.

“I’m not a hydrologist, but based on what I have come to understand about the area, there is no significant risk of seeping into an underground water course. Even if it were to occur, there’s nothing in the lake in concentrations to cause concern,” he said.

Samples will be taken during the first month to check for any changes in the material, he said. If something is detected, it will be monitored.

Commissioner Lynn Willard asked if core sampling was conducted at the quarry and suggested that might be advisable before material is dumped there. Richardson said no core samples were taken, but “it’s solid rock all the way down.”

Stokes said he owns Copper Mountain quarry and about 1,000 acres east.

“The quarry is solid granite laced with clay,” he said. "(R.D. Hubbard) dug a deep well east of the quarry and the granite went 200 feet before they hit sand stone. I see no permeability problem. It’s not going anywhere.

“When we started this process, Richardson gave me a set of requirements to make our site eligible” and receive the necessary state Environment Department permit. He said the nearest spring is more than one mile away. He hired an environmental firm in Albuquerque and told officials to design the quarry area “just like a solid waste facility.”

A sump pump and catchment basins are part of the design to ensure moisture is evaporated. The design costs him $60,000, he said, adding, "we didn’t skimp on this.”

Richardson also wanted a five year post-closure care to ensure no sediment runoff occurs.

“I agreed to that,” Stokes said. “I think you have as safe a site as you can have.”

Richardson said while he understood the concerns of the commission, the material to be deposited in the quarry is essentially dry and the water table there is at 200 feet or greater depth.

The USACE permit requires documentation on compactions, final grades in the quarry and plans for containing runoff on site, he said.